System and method of stacking network switches

A network switch system, comprising:

• a plurality of first-level switches operating in a slave mode, the first-level switches providing a plurality of local ports for receiving and sending network packets;
• and
• a plurality of second-level switches operating in one of brain mode or master mode,
• wherein, the first-level switches includes a plurality of upward ports connecting to the second-level switches, each of the first-level switches and the second-level switches having a forwarding database,
• wherein the first-level switches sends the refresh packets to the second-level switches for synchronizing the forwarding databases of the second-level switches,
• wherein the second-level switches providing packet communications among the first-level switches, and
• wherein a second-level switch operating in the brain mode providing refresh packets to the first-level switches for synchronizing the forwarding databases of the first-level switches.

A method for operating a network switch in a slave mode within a network switch system, the slave switch having a forwarding database, comprising:

• receiving a network packet;
• sending an outgoing refresh packet to neighboring switches when the network packet contains address information that the slave switch has no corresponding record in the forwarding database of the slave switch, or the network packet contains address information that corresponding address entries in the forwarding databases of the neighboring switches have expired, wherein the slave switch sends the outgoing refresh packet to synchronize the forwarding databases of the neighboring switches;
• registering the address information of the network packet to the forwarding database of the slave switch;
• and
• registering the address information of an incoming refresh packet to the forwarding database of the slave switch upon receiving the incoming refresh packet.

A method of operating a network switch in a brain mode within a network switch system, the brain switch having a forwarding database, comprising:

• receiving a network packet;
• sending an outgoing refresh packet to neighboring switches when the network packet contains address information that the forwarding database of the brain switch has no corresponding address entry, the network packet contains address information that corresponding address entries in the forwarding databases of the neighboring switches have expired, or the brain switch receives an incoming refresh packet from the neighboring switches, wherein the brain switch sends the outgoing refresh packet to synchronize the forwarding databases of the neighboring switches;
• and
• registering the address information of the network packet to the forwarding database of the brain switch.

A method of operating a network switch in a master mode within a network switch system, the master switch having a forwarding database, comprising:

• receiving an incoming network packet;
• registering address information of an incoming refresh packet to the forwarding database of the master switch upon receiving the incoming refresh packet;
• looking up the destination port of the incoming network packet in the forwarding database of the master switch;
• sending the incoming network packet to the destination port;
• and
• broadcasting the incoming network packet when the forwarding database does not have corresponding destination port information.

A method for stacking network switches, comprising:

• providing a plurality of network switches for providing an exchange of network packets;
• providing a forwarding database for each of the network switches;
• providing at least one refresh packet to synchronize the forwarding databases of the plurality of network switches upon receiving the network packets;
• and
• registering the refresh packet for each of the plurality of network switches to the forwarding databases.